Woven wire screen and method of making same



Oct. 27, 1931. BOEHM WOVEN WIRE SCREEN AND METHOD OF MAKING SAME Filed Dec. 27, 1927 2 Sheets-Sheet l mmvroza. B0 8 A? m BY I ATTORNEYS.

Oct. 27, 1931. J. BOEHM 1,829,498

WOVEN WIRE SCREEN AND METHOD OF MAKING SAME Filed Dec. 27. 1927 2 Sheets-Sneak 2 IN VEN TOR Patented Oct. 27, 1931 UNITED STATES PATENT OFFICE JOHN 30m, 01 CLEVELAND, OHIO, ASSIGNOB TO THE w. B. TYLER COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO WOVEN WIRE SCREEN AND METHOD 0] MAKING SAME Application filed December 27, 1927. Serial No. 242,721.

The present invention, relating as indicated to a woven wire screen and method of making same, is particularly directed to an improved screen having a materially greater life than those now in general use and to a of many types of screens to become sleazy To the accomplishment of the foregoingand related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims; the annexed drawings and the following description setting forth in detail one method and one product exemplifying my invention, such disclosed procedure and product constituting, however, but one of various applications of the principle of my invention.

In said annexed drawings 1- Fig. 1 is a plan view of one of my improved screens; Fig. 2 is a cross-sectional view taken on the line 22 of Fig. 1; Fig. 3 is a plan view of another type of screen; Fig. 4 is a section on the line 4-4, Fig. 3; Fig. 5 is a plan view of still another type of my improved screen, Fig. 6 is a similar view of still another modification; Fig. 7 is a side elevation of one of the precrimped wires used in my improved screen; Fig. Sis a section on the line 88, Fig. 7 and Fig. 9 is a side elevation partially in section illustrating one form of apparatus which may be employed to produce the precrimped wires employed in making my improved screen.

In the ordinary woven wire screen employed'for industrial purposes the wires of one of the two series are preliminarily crimped or formed to bring them. to approximately the desired final contour, and these preformed wires are then interwoven with the other series which are sometimes entirely unformed, although they also may be preformed if desired. The preforming of the wires involves the bending or crimping of the wires to produce a series of alternated bends on either side of the original plane of the wire to form the knuckles which pass res ectively over and under the wires of the ot er series. In order to keep the wire in condition for this severe bending it must be kept relatively soft since the bending increases the temper and hardnessat the bent portion, and hence the ntermediate portion is materially softer than is really'necessary in order to secure the maximum life for the screen and the maximum wearing capacity under the abrasive action of the material passing over and through the screen.

My improved screen involves the use of preformed wires in either one or both series, but of a new and distinct character which requires materially less working of the material during the forming and hence permits the use of a materially harder wire to begin with, thus giving the entire wire a greater temper and toughness and hence a considerably longer life in actual use.

Referring now to Fig. 1, there is shown a screen having square mesh formed by two series of wires interengaged at right angles to each other. Of these series, the one including the wires 1, which may be termed the longitudinal wires, are not preliminaril crimgled or formed. The other series, includ ing t e wires 2, which may be termed the transverse wires, are provided with preformed bends or crimps in the manner to be hereinafter explained. It will be understood that screens embodying the present invention may be made in either square or rectan lar meshes and with either one or both series of wires preformed in the manner now to be explained, depending upon the particular service and use to which the screen is to be put.

In the screen shown in Fig. 1 each transverse wire 2 (see Fig. 2) is provided with spaced and alternated bends or crimps 3 and 4 and intermediate lesser bends or crimps 5 and 6. The longitudinal wires 1 are woven into the screen fabric and nest in the deep crimps 3 and 4 so that the engaging face of crimp 4 with longitudinal wire 1 is spaced above the engaging face of crimp 3 with lower longitudinal wire 1 a distance which is less than the thickness of the longitudinal wire 1. In other words, if a plane be drawn through the engaging faces of the upwardly directed crimps this plane would very nearly coincide with a similar plane drawn through the engaging faces of the downwardly d irected crimps. In this manner the longitudinal wires are placed in, tension which lends strength to the screen. One method of forming the wire in this manner is illustrated in Fig. 9 and consists in passing a straight wire 10 between cooperative rolls 11 and 12, each of which is provided with a series of spaced dies 13 and with intermediate dies 14 of lesser size than the dies 13.

The dies on the upper and lower rolls are alternated with respect to each other to engage the wire in the manner shown in Fig. 9, that is, with one of the teeth 13 for example contacting the upper surface of the wire and two of the intermediate teeth 14 on the lower roll engaging the lower surface of the wire at points equidistantly spaced from the plane of engagement of the large die 13 on the upper side. As the rolls are rotated the wire is alternately crimped, as shown in Fig. 9, producing alternate-and spaced deep crimps 3 and 4 and intermediate alternated smaller crimps 5 and 6. In this manner of crimping, the bending of the wire at any one point is minimized and that portion of the wire lying between the alternated deep crimps, which is the portion of the wire shown between the dotted lines a and I) (see Fig. 2) is brought into substantially the same plane. If the crimps 5 and 6 were omitted it will be evident that the wire would extend in a perfectly straight line between the deep crimps 3 and 4;. These would not produce the same angle of engagement between transverse and longitudinal wires that has been found necessary to prevent sleaziness and to maintain regularity of openings. On the other hand, if the deep crimps extend through a sufficient angle to produce the same engagement that is secured in the present screen. then an additional deep intermediate crimp is required in order to return the wire to such a point between longitudinal wires that it can be again bent through the required angle in passing around the next longitudinal wire. This deep crimping, and particularly the intermediate deep crimps, in screens made up to the present time, has caused an excess working and tempering of the metal at the crests of these crimps. To avoid this the wire initially had to be left in entirely too soft a condition to secure long life, or if the wire were initially tempered by being drawn to the required degree, then the bends of the crimps became over-tempered in the former and were made brittle. Thesev difiiculties are avoided by the introduction of the lesser intermediate crimps, and they not only eliminate the daner of over tempering the wires at the bends. but they permit the use of a wire sufliciently tempered to a greater degree than formerly, while bringing the intermediate portions of the transverse wires into substantially the same horizontal plane.

In Fig. 3 I have illustrated a rectangular screen in which precrimped transverse wires 15 are employed and uncrimped longitudinal wires 16. In Fig. 5 I have shown a square mesh screen in which precrimped longitudinal wires 18, and also precrimped transverse wires 19, are employed. Similarly, in Fig. 6 I have shown a screen having both rectangular and square meshes and in which the transverse wires 20 only are precrimped, and it will be understood that other variations in this respect may be employed.

Other forms may be employed embodying the features of my invention instead of the one here explained, change being made in the former construction, provided the elements stated by any of the following claims or the equivalent of such stated elements be employed, whether produced by my preferred method or by others embodying steps equivalent to those stated in the following claims.

I therefore particularly point out and distinctly claim as my invention 1. A precrimped warp wire for use in combination with chute wires of woven wire screens, having heavy and light crimps therein, said light crimps facing oppositely and being between said heavy crimps, said heavy crimps facing oppositely and having their engaging faces spaced in a plane at right angles to that of the screen less than the thickness of the wire to be interwoven therewith.

2. A precrimped warp wire, for use in combination with chute wires of Woven wire screens, consisting of a hard drawn wire provided with heavy and light crimps, said heavy crimps facing oppositely and having their engaging surfaces spaced in a plane at right angles to that of the screen a dis: tance less than the thickness of the wire to be interwoven therewith.

3. A woven wire screen consisting of series of warp and chute wires, one of said series being formed of hard drawn wire and being provided with spaced oppositely facing 0btuse-angled crimps having their engaging faces spaced in a plane at right angles to that of the screen a distance less thanthe thickness of the wires of said other series, and having also light intermediate crimps, said light crimps facing oppositely and being between said obtuse-angled crimps.

4. A woven wire screen consisting of series of-warp and chute wires, both of said series of wires being hard drawn wires and being provided with spaced oppositely facing obtuse angled crimps in a plane at right angles to that of the screen having their engaging faces spaced a distance less than the thickness of the wires of the other series engaged therewith, whereby all of said wires are placed in a tensioned engagement, and

one of said series of wires being provided with intermediate shallow crimps, permitting the portions of said wires between said heavy crimps therein to lie in approximately the same plane.

5. In a method of precrimping screen wires, the steps which consist in forming successively a deep downwardly facing crimp, a shallow upwardly facing crimp, a shallow downwardly facing crimp and a deep upwardly facing crimp, repeating these steps so as to make a wire, for use in screens, having oppositely facing light crimps between oppositely facing deep crimps, the wire-engaging faces of said deep crimps being spaced less than the thickness of a wire to be interwoven therewith.

6. In a method of precrimping screen wires, the steps which consist in forming deep crimps which open in opposite directions, and shallow crimps which open in opposite directions to each other and to the deep crimps, repeating these steps so as to make a wire, for use in screens, having oppositely facing light crimps between oppositely facing deep crimps, the wire-engaging faces of said deep crimps being spaced less than the thickness of awire to be interwoven therewith.

7. A precrimped wire for use in woven wire screens having deep and light crimps, said deep crimps facing oppositely and being adapted to receive transverse wires,'the point of contact of a deep crimp with an upper transverse wire being spaced less than the thickness of said transverse wire above the point of contact of an adjacent deep crimp with a lower transverse wire.

Signed by me this 22d day of December,

JOHN BOEHML 

